Remembrance + Mortuary + Umbral Collar Zealot + Shield Sphere

Remembrance

Mortuary

Umbral Collar Zealot

Shield Sphere

How it works

1. Activate Umbral Collar Zealot by sacrificing Shield Sphere.
2. When Shield Sphere dies, Mortuary and Remembrance trigger.
3. Resolve the Mortuary trigger, putting Shield Sphere from your graveyard on top of your library.
4. Resolve the Remembrance trigger, searching your library for Shield Sphere and putting it into your hand.
5. Resolve the Umbral Collar Zealot ability.
6. Cast Shield Sphere by paying 0.
7. Repeat.